SHANGHAI (REUTERS) - The former chairman of China Guangfa Bank Co Ltd, part-owned by Citigroup Inc., is being investigated on suspicion of taking bribes, prosecutors said on Thursday, the latest official caught up in a widening corruption crackdown.

President Xi Jinping's push to counter graft and extravagance has ensnared a series of senior bankers, with the 2013 investigation into the former vice president of Agricultural Bank of China Ltd being one of the most high-profile.

An investigation into Li Ruohong, chairman of Guangfa from 1999 to 2009, is going on, said prosecutors in the southern province of Guangdong in a notice posted on The Supreme People's Procuratorate official website.

They did not elaborate on the allegations or say how long the investigation would take.

A Guangfa Bank official declined to comment when contacted by Reuters, merely saying the bank "did not have a grasp of the situation at present".

Li could not be reached for comment.

In 2011, the bank, previously known as Guangdong Development Bank, was reportedly considering a dual-listing on the Hong Kong and Shanghai stock exchanges.